The book is likely older than 1980 and it is older than 1990. It’s set on an alien ancient abandoned planet sized world construct. The humans go down levels to salvage what they can from the frozen levels. The stuff is better preserved as they go farther towards the core. The main character penetrates farther than has been done in the past and finds stuff is still functioning and it’s getting warmer. They penetrate far enough that the area is warm and has animals and plants living in there. They find there are civilizations living farther down than that in lower levels.
I’m pretty sure I read this at some point, but can’t remember the title. I can’t even remember for sure if it was a full novel or more of a novella/short story. But now I want to know, so I’m bumping your thread.
I’ve read a lot of “The Big Enormous Alien Thing” stories, but these details do not resonate with me.
This bears some resemblance to Greg Bear’s Eon, and Robert Reed’s Marrow; more details, please!
P.S. This list also has some possibilities http://groups.google.com/group/rec.arts.sf.written/msg/a594356f3c70b1af?hl=en&&q=megastructure+group%3Arec.arts.sf.written including “Journey to the Centre” by Stableford, which might be your book.
I don’t have more details. I read it 30 years ago.
Journey to the Centre triggers familiarity. Looking at the page I’d say it has to be the story. I only ever read the first book and knew there had to be more.
Journey to the Centre
Invaders from the Centre
The Centre Cannot Hold
by Brian Stableford
That is the book.
Thanks
Glad to help.